1. Field of the Invention
The present invention relates to a golf ball comprising a solid core, an intermediate layer, and a cover having a multiplicity of dimples formed on its surface. More particularly, the invention relates to a golf ball having an optimum balance in hardness between the core, the intermediate layer and the cover, and having suitable dimple characteristics, thus presenting both a good feel when hit with a club and improved flight performance regardless of the club head speed.
2. Prior Art
With the rise in the golfing population in recent years, the attributes that golfers look for in a golf ball have become more diverse and individualized. The desire is especially strong for golf balls having greater flight distance and a better feel. This has led to numerous investigations on ball construction, dimple parameters and so forth.
For instance, golf balls having a variety of constructions are available today on the market, but the majority of commercial golf balls are either two-piece solid golf balls made of a rubber-based core and a cover composed of ionomer resin or the like, or thread-wound golf balls composed of a thread-wound core obtained by winding rubber thread about a solid or liquid center, and a cover formed over the core.
Most golfers of ordinary skill use two-piece golf balls because of their excellent flight performance and durability. However, these balls have a very hard feel, in addition to which the rapid separation of the ball from the head of the club results in poor control. For this reason, many professional golfers and skilled amateurs prefer using thread-wound balls to two-piece solid balls. Yet, although thread-wound golf balls have a superior feel and control, their distance and durability fall short of those for two-piece balls.
Thus, two-piece golf balls and thread-wound golf balls today provide mutually opposing features, and so golfers select which type of ball to use based on their level of skill and personal preference.
This situation has prompted efforts to achieve the feel of a thread-wound ball in a solid golf ball, as a result of which a number of soft two-piece solid golf balls have been proposed. A soft core is used to obtain such soft two-piece balls, but making the core softer lowers the resilience of the golf ball and compromises flight performance and durability. As a result, not only do these balls lack the excellent flight performance and durability characteristic of ordinary two-piece solid golf balls, they are often in fact unfit for actual use.
Furthermore, these golf balls have generally been made to serve the needs of high head speed players, such as the professional golfer and the skilled amateur golfer. When they are used by low head speed players such as beginners, seniors and ladies, they are unsatisfactory both in terms of distance and feel.
Numerous studies have also been done on dimple characteristics, such as the dimple shape (e.g., depth and diameter), dimple configuration, and various dimple parameters, but there remains considerable room for improvement. The increasingly diverse and individualized desires of golfers have yet to be fully met.